Leases - Rental Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Rental Equipment [Abstract]
Rental equipment, primarily wireless recording equipment	$ 90,399	$ 114,783
Accumulated depreciation and impairment	(52,017)	(60,466)
Rental equipment, net	$ 38,382	$ 54,317